in the link tag. The ref to the file ‘style.css’ is described as a stylesheet by rel. Are there any times when a stylesheet isn’t a text file?
What does type="text/css" additionally tell us that we really need to know before we can incorporate the CSS file?

In pre-HTML5 browsers, it declares the MIME type the browser should expect. The type attribute value should match the MIME type written into the file header. HTML5 has made CSS the de facto standard for style sheets and no longer requires us to declate the type. The relation declaration is still required.

All in all, declarations in the meta data are for the browser to know, not the user.